HPOWEB relies heavily on the fantastic, true-color, 6-inch-per-pixel, aerial imagery served up by NC One Map. In 2010 the entire state was flown, and since 2012 a separate quarter of the state’s 100 counties have been updated with new imagery each year. NC One Map will soon release 2016 imagery of the coastal counties.

NC One Map also provides statewide coverage from 1998 and 1993, as well as a composite image of the latest imagery for any area to which you are zoomed in. We have decided to make these imagery datasets more easily available within HPOWEB by modifying the Background View grid.

The General Audience version of HPOWEB (accessible here) now shows the three statewide imagery layers on the second line of the grid, while the most recent aerial imagery layer is in the middle top row.

The 1998 imagery is infrared, which makes vegetation appear reddish and water features blackish. It can often help distinguish human-made objects from surrounding trees.

The 1993 imagery is black and white and of a much lower spatial resolution than the recent imagery. Still, it can help locate structures no longer extant – or confirm historic field patterns in an area lost to development.

The Advanced User version of HPOWEB (accessible here) also displays these four imagery layers in the same positions, but note that a few additional background views – including two more topographic views and a Dark Gray basemap – are available in this version.

The individual images of the “Most recent aerial” may range from 2011-2015, and this date range will roll year by year as new imagery is flown. For instance, the coastal counties had imagery flown in 2011, but when the 2016 images become available, the date range will be listed as 2012-2016. (You can see a map of which counties were flown each year, here.)

One benefit of using a Geographic Information System (GIS) computer mapping software is the ability to overlay historic paper maps on contemporary aerial imagery. The HPOWEB mapping website now provides users the opportunity to view over a dozen maps published between 1865 and 1929 in this manner.

The first step to viewing historic paper maps “at their real-world location” is to scan, or digitize, the drawing. Next, the resulting digital image must be pinned to coordinates at the location it represents – a process called georeferencing. In this way, the GIS software will know, for example, that a map of Surry County should “show up” not in the Atlantic Ocean, but rather in northwestern North Carolina.

The good folks at the University of North Carolina at Chapel Hill have georeferenced over 150 historic maps – a collection that includes county soil surveys, highway maps, town plans, and an 1884 map depicting the “former territorial limits of the Cherokee Nation of Indians”. Each map contains a plethora of details of great interest to historians, archaeologists, and arm-chair culturalists.

The Historic Preservation Office GIS staff have incorporated 14 of these maps into HPOWEB so that users can not only see the historic map in relation to contemporary aerial imagery, but also in relation to historic resources that have been previously surveyed and mapped by the office.

From the toolbar, click on the Advanced Tools icon (it looks like a toolbox with a white plus sign), and then on the first option, Map Services.

In the Enter Keyword text box, type historic, and then click the Find Data button.

The first match in the list of choices at the bottom of the dialog box is NC Historic Maps.

Hover over the name and, once the yellow highlight appears, click the Load Service button.

The scanned, georeferenced historic paper maps will display in HPOWEB across the state. At this point, you can minimize or close the Map Services dialog box.

The service is listed as a new layer at the top of the HPO Data Layers content list. Note that you can see which historic maps we have displayed by clicking on the small grey arrow to the left of the layer name.

Zoom into the southern portion of the Surry County map, published in 1921 by the North Carolina Geological and Economic Survey. The map displays schools, houses, churches, installed and suggested water transmission lines, and developed and undeveloped dam sites.

Next, zoom in further to see the Little Richmond School.

Since the NC Historic Maps layer is at the top of the HPO Data Layers content list, it obscures the other HPO map data listed below it. Move the NC Historic Maps layer down the list by clicking on the small grey arrow to the right the layer name, and then clicking the option to Move down.

After doing this once, the HPO Data points will appear on top of the historic map (the boundary shading is still below the historic map). Note that there is a surveyed point for the c. 1920 Little Richmond School, though it is no longer extant, having been moved or demolished sometime before 1993.

Just to the east of the Little Richmond School is another school labeled Col. on the Surry County map. Might this be a Rosenwald School? While no school currently exists at this spot, either, knowing the location of this second school could provide very useful to a historian researching the education of African-American students of Surry County.

We hope users find this new addition of old maps helpful. Let us know if you would like us to add another of UNC’s collection of georeferenced maps to HPOWEB – or perhaps a digitized map from your own collection!

As of this week, users of HPOWEB can now display the parcel boundaries of 25 counties across North Carolina!

These parcel data are provided as a service by NC One Map as their initial foray into creating a single, standardized parcel boundary GIS layer for the entire state. This is remarkable considering that every county tax assessor collects a slightly different set of data – and maintains these data in slightly different ways (think of how many different types of parcel numbers you’ve ever seen).

Read more below. This new functionality is only available in the Advanced User version of HPOWEB – not the General Audience version.

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Within HPOWEB, you’ll notice that Parcels has been added as a new HPO Data Layer. It sits near the bottom between Boundary shading and Base Data. It is checked off when HPOWEB is first opened. Also notice that there are four sublayers.

It will be easier to view the Parcels layer (at least initially) after checking OFF the All NC HPO Data and Boundary shading layers. Then check ON the Parcels layer.

Each of the four sublayers automatically displays (and un-displays) at different scales. At a statewide scale, County Boundaries displays as dashed yellow lines and Counties Contributing Parcels displays as solid grey. Notice that the first 25 participating counties are spread out across the state and include both rural and urbanized areas.

As you zoom in, the Parcel Centroids (blue dots in the center of the lots) will display – they turn on at a 1:200,000 scale. Closer still, Parcels (blue lines marking the boundary of each lot) comes on – at a 1:40,000 scale.

Here’s an example of Trenton, NC in Jones County. You can click on any parcel to get a pop-up information box of basic data.

Be aware of some issues regarding the data:

Consult the county tax assessor for the most current data

Attributes like Year built can be inaccurate

Exercise caution with the parcel numbers. For instance, the Durham County data references an old PIN, not the newer Parcel ID employed by the tax assessor.

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In addition to clicking on individual parcels to obtain information, you can also use a new Zoom to Parcel tool that we have added to the toolbar.

If you know the parcel number of a property – but not where it is located – you can search for it using this tool. (Caveats include the current 25-county limit and the caution mentioned in the previous paragraph.)

To speed the search, we recommend adding the County name, too. The example in the tool suggests entering “Wake” and “1704706147”. If you do that and click search, you’ll find a match for the example parcel. Click the Zoom to button once to drill all the way down to the parcel.

We are uncertain when the remaining 75 counties will be added to this service, but we sure do appreciate what they’ve accomplished so far!

In addition to our interactive web map – HPOWEB, in addition to the streamable web map services we publish, and in addition to our mobile app you can use with your phone or tablet to discover historic resources “in the field”, we are now offering a data download so that you can work directly with our data in your native GIS environment.

Access our GIS data from within HPOWEB by selecting the Data Download button in the toolbar. (This tool is not available from the General Audience version of HPOWEB, but rather only from the Advanced User version.)

Users can now select the Data Download icon in the HPOWEB toolbar to download GIS data

Users can save a zipped file to their local machine. We will update this zipped file monthly, so users are encouraged to check HPOWEB for a live view of the HPO geodatabase, which is updated with new features (and attribute data) on a daily basis.

The zipped file contains all historic resource data displayed in HPOWEB (as of the date of extraction), including both points and polygons, across the entire state of North Carolina – currently almost 70,000 places.

After you download the data, please consider filling out our feedback form to help us understand who uses historic resource data and how we can continue to improve its delivery. Thanks!